* stats.html: update Raspberry Pi Zero W comparison

This is also a start for a little restructure, comparing multiple distros in a matrix per SBC, to reduce the competition impression against individual other distros. However, there is no Armbian for 32-bit Raspberry Pi models, and I was too lazy to dig out another notable dpkg-based distro for those.

* Add Raspberry P 5 distro matrix to comparison page

Also fix RPi Zero W disk usage: A new rpi-swap tool and config kept recreating /var/swap, with a theoretical RAM size (512 MiB) muliplier of 1, even that it is not used, but an as well pre-configured zram partition instead. However, a fair comparison is only possible without any swap space that is not RAM-based, like a zram partition.

* Add comparison matrix for Odroid XU4

* Add comparison matrix for NanoPi R76S

And remove mixitup for thumbnail sorting/filtering: Pretty overkill for such a small number of thumbs.

* app.js: do not attempt to call mixitup if it has not been loaded

* Remove "Allo" filter as we do not offer Sparky SBC iamges anymore